We've had the best results by combining a few things.
First, standard convex mirrors help with basic side and rear coverage, but the heavy lifting comes from multi-camera systems.
We use rugged, wide-angle cameras pointed directly at all machine blind spots, feeding to a dedicated in-cab monitor.
Crucially, we've implemented radar-based proximity detection. This system is the real safety net since it alerts the operator when anything gets too close to the machine's path, regardless of where they're looking.
Just make sure any tech is industrial-grade to handle the dust and vibration. It's a key investment for incident prevention!